This invention relates generally to electric motors and more specifically to three-phase electric motor voltage connections.
At least some known electric motors are constructed to operate at different voltages using power supply voltages available in conventional power distribution systems. Typically, three-phase motors operate at either 230 volts or 460 volts depending on the particular application and the available voltage. Three-phase electric motors include a winding for each phase, and each phase winding includes two groups of coils. The leads of each coil group are coupled to a junction box for connection to a power source. The leads may be connected in several different configurations to electrically configure the motor for operation at a predetermined voltage. For example, when the coils of each of the phase windings are connected in series, the motor may operate at twice the voltage that is possible when the coils of each phase winding are connected in parallel. Known voltage change devices for three phase electric motors are costly and difficult to assemble. In addition, known voltage change devices may be difficult to use, and may have reliability problems in the field.